I thought I would share the website I just ran across! It looks really good. You just have to type in the kind of food and it gives the the GI and carb values.
Is is based at the University of Sydney, so those down under may find more specific food items on there, but it does state which country the food is from that they test.
It also appears they are working on a labeling standard for food, which would be really helpful for those trying low carb
Happy surfing!
http://www.glycemicindex.com/
Amie